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United States Patent |
5,090,446
|
Hunter
,   et al.
|
February 25, 1992
|
Adjustable check valve
Abstract
An adjustable pressure check valve comprises a generally cylindrical body
having a throughbore communicating with an inlet and an outlet at opposite
ends thereof, an annular valve seat in the throughbore, a valve member
having a sealing surface for engagement with the seat disposed in the bore
for movement into and out of engagement with the seat, a compression
spring disposed in the throughbore for biasing the valve member into
engagement with the seat, and an adjusting member for adjusting the
biasing force of the spring on the valve member.
Inventors:
|
Hunter; Edwin J. (Rancho Santa Fe, CA);
Scott; Loren W. (Carlsbad, CA)
|
Assignee:
|
Edwin J. Hunter (Rancho Santa Fe, CA)
|
Appl. No.:
|
629724 |
Filed:
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December 17, 1990 |
Current U.S. Class: |
137/540; 251/337 |
Intern'l Class: |
F16K 015/02 |
Field of Search: |
137/540,542,543.17
251/337
|
References Cited
U.S. Patent Documents
3422840 | Jan., 1969 | Bryant et al. | 137/540.
|
4049017 | Sep., 1977 | Jones | 137/540.
|
4265271 | May., 1981 | Rosaen et al. | 137/540.
|
4718442 | Jan., 1988 | Nicoll | 137/540.
|
Primary Examiner: Schwadron; Martin P.
Assistant Examiner: Lee; Kevin L.
Attorney, Agent or Firm: Baker, Maxham, Jester & Meador
Claims
We claim:
1. An adjustable pressure check valve comprising:
a generally cylindrical body having a throughbore communicating with an
inlet and an outlet at opposite ends thereof, said throughbore having
inwardly and longitudinally extending ribs;
an annular valve seat in said throughbore;
a valve member having a sealing surface for engagement with said seat
disposed in said bore for movement into and out of engagement with said
seat;
compression spring means disposed in said throughbore for biasing said
valve member into engagement with said seat; and
adjusting means accessible exclusively via said outlet for adjusting the
biasing force of said spring on said valve member, said adjusting means
comprises a threaded member having external threads threadably engaging
said ribs in said through bore and having an annular shoulder engaging
said spring.
2. An adjustable pressure check valve according to claim 1 wherein:
said spring means comprises an elongated coil spring having one end
engaging said valve member and an other end engaging said adjusting means;
and
said threaded member having an annular shoulder engaging said other end of
said spring.
3. An adjustable pressure check valve according to claim 1 wherein:
said valve member comprises a circular disc having an elongated coaxial
stem extending from one side thereof, and a retaining pin extending from
the other end and
a sealing washer on said retaining pin for engaging said valve seat.
4. An adjustable pressure check valve according to claim 1 wherein:
said throughbore is coaxial of said body;
said annular valve seat is coaxial of said throughbore; and
said valve member is disposed coaxially of said throughbore.
5. An adjustable pressure check valve according to claim 1 wherein:
said threaded member having an annular shoulder engaging said spring.
6. An adjustable pressure check valve according to claim 1 wherein:
said threaded member has a coaxial throughbore, and said valve having a
stem which is reciprocally mounted in said throughbore.
7. An adjustable pressure check valve comprising:
a generally cylindrical body having a throughbore communicating with an
inlet and an outlet at opposite ends thereof, said throughbore having
inwardly and longitudinally extending ribs;
an annular valve seat in said throughbore;
a valve member having a sealing surface for engagement with said seat
disposed in said bore for movement into and out of engagement with said
seat;
compression spring means disposed in said throughbore for biasing said
valve member into engagement with said seat; and adjusting means
accessible exclusively via said outlet for adjusting the biasing force of
said spring on said valve member, said adjusting means comprises a
threaded member having external threads threadably engaging said ribs in
said throughbore and having an annular shoulder engaging said spring;
said thread member has a tool fitting for receiving a torque applying tool
at said outlet, and a valve member including a stem positioned to displace
a tool therefrom for limiting the adjustment thereof in one direction, and
said body includes shoulder means for limiting adjustment thereof in the
other direction for limiting the adjustment of the pressure of said valve.
8. An adjustable pressure check valve according to claim 7 wherein:
said tool fitting is a cross slot for receiving a screwdriver.
9. An adjustable pressure check valve comprising:
a generally cylindrical body having a coaxial throughbore communicating
with an inlet and an outlet at opposite ends thereof, said throughbore
having inwardly and longitudinally extending ribs;
an annular valve seat coaxial of said throughbore adjacent said inlet end;
a valve member comprising a circular disc having an elongated coaxial stem
extending from one side, thereof, a retaining pin extending from the other
end, and a sealing washer on said retaining pin having a sealing surface
for engagement with said seat disposed in said bore for movement into and
out of engagement with said seat;
an elongated coiled compression spring disposed in said throughbore in
compressive engagement with said valve member for biasing said valve
member into engagement with said seat; and
adjusting means threadably engaging said body on the outlet side of said
valve seat for adjusting the biasing force of said spring on said valve
member, said adjusting means comprises a threaded member having external
threads threadably engaging said ribs in said throughbore and having an
annular shoulder engaging said spring.
10. An adjustable pressure check valve according to claim 9 wherein:
said threaded member having an annular shoulder engaging said spring.
11. An adjustable pressure check valve according to claim 10 wherein:
said threaded member has a coaxial throughbore, and said valve stem is
reciprocally mounted in said throughbore.
12. An adjustable pressure check valve according to claim 11 wherein:
said threaded member has a tool fitting for receiving a torque applying
tool at said outlet, and said stem is positioned to displace a tool
therefrom for limiting the adjustment thereof in one direction, and said
body includes shoulder means for limiting adjustment thereof in the other
direction for limiting the adjustment of the pressure of said valve.
13. An adjustable pressure check valve according to claim 12 wherein:
said tool fitting is a cross slot for receiving a screwdriver.
14. An adjustable pressure check valve comprising:
a generally cylindrical body having a coaxial throughbore communicating
with an inlet and an outlet at opposite ends thereof, said throughbore
having inwardly and longitudinally extending ribs;
an annular valve seat coaxial of said throughbore adjacent said inlet;
a valve member comprising a circular disk having an elongated coaxial stem
extending from one side thereof, a retaining pin extending from the other
end, and a sealing washing on said retaining pin having a sealing surface
for engagement with said seat disposed in said bore for movement into and
out of engagement with said seat;
an elongated coiled compression spring disposed in said throughbore in
compressive engagement with said valve member for biasing said valve
member into engagement with said seat; and
adjusting means accessible at said outlet for adjusting the biasing force
of said spring on said valve member, said adjusting means comprises a
threaded member having external threads threadably engaging said ribs in
said throughbore and having an annular shoulder engaging said spring.
15. An adjustable pressure check valve according to claim 12 wherein:
said threaded member has a coaxial throughbore, and said valve stem is
reciprocally mounted in said throughbore.
16. An adjustable pressure check valve according to claim 15 wherein:
said threaded member has a tool fitting for receiving a torque applying
tool at said outlet, and said stem is positioned to displace a tool
therefrom for limiting the adjustment thereof in one direction and said
body includes shoulder means for limiting adjustment thereof in the other
direction for limiting the adjustment of the pressure of said valve.
17. An adjustable pressure check valve according to claim 14 wherein:
said tool fitting is a cross slot for receiving a screwdriver.
Description
BACKGROUND OF THE INVENTION
The present invention relates to valves and pertains particularly to an
improved adjustable pressure check valve.
Check valves are widely used to prevent back flow in a fluid system. This
also prevents lines of the system from draining. They are also used to
prevent flow until a certain minimum line pressure is achieved.
Some fluid systems may employ several check valves of different pressure
settings. For example, some irrigation systems may have sprinkler units
positioned at different elevations. This may require check valves for
controlling pressure at the different elevations in order to obtain
uniform flow rates at the different elevations.
It is preferable that check valves be adjustable in order to avoid the
necessity of stocking many different valves. While adjustable check valves
are known, they require removal from the system for access to both inlets
and outlets thereof for adjustment.
It is desirable that a simple and easily adjustable check valve be
available.
SUMMARY AND OBJECTS OF THE INVENTION
It is the primary object of the invention to provide an improved adjustable
check valve.
In accordance with a primary of the present invention, a check valve
includes adjustable means for adjusting the pressure thereof within
predetermined limits.
BRIEF DESCRIPTION OF THE DRAWING
The above and other objects and advantages of the present invention will
become apparent from the following description when read in conjunction
with the accompanying drawings wherein:
FIG. 1 is a side elevation view in section of a preferred embodiment of the
invention;
FIG. 2 is a section view taken generally on line 2--2 of FIG. 1; and
FIG. 3 is a front elevation view of an irrigation system embodying a check
valve in accordance with the invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Referring to the drawing, and particularly to FIGS. 1, and 2, there is
illustrated an exemplary embodiment of the invention, designated by the
numeral 10. The invention comprises an adjustable check valve wherein a
pressure of the check valve may be adjusted from the end of the valve unit
without the necessity of access the other end. It is oriented such that
the access is the outlet of the valve so that it may be mounted on a riser
or the like and may be adjusted while connected to a of water and under
pressure.
The valve unit comprises a gene tubular body 12 having an inlet 14 with
suitable or the like for attachment to a riser or the like, and an outlet
port 16 having external threads in the illustrated embodiment for
connection of distributing lines of the like The throughbore is formed
near the inlet end with an annular valve seat 20 surrounding a passage
into a normally larger diameter section of the housing, with a plurality
of elongated inwardly extending ribs 22 extending substantially the length
thereof.
A check valve member comprising an annular disc 24 on a forward end of an
elongated stem 26 includes a retaining pin 28 on the forward end of the
disc for retaining a washer seal 30 in place on the end of the stem backed
by the disc 24. The washer or disc 30 is preferably formed of a suitable
elastomeric material, such as a rubber or the like, and sealingly engages
the annular valve seat 20 for closing and preventing flow through the
valve
A retaining nut 32 having an annular recess formed of inner and outer
sleeves 34a, 34b, respectively, forms an annular recess for receiving one
end of a coil spring 40, and has an inner bore 36 for receiving an upper
end and portion of the valve stem 26. External threads 38 formed on the
nut or retainer member 32 threadably engage the housing bore, specifically
the inner edges of ribs 22 for screwing the nut downward or inward against
the outer end of the spring, increasing the force of the coiled
compression spring 40 against the valve disc 24 and the retaining nut. The
nut 32 is located on the outlet side of the valve seat. It is preferably
made of a harder material than that of the housing and ribs to be
self-threading. The ribs provide a water flow passage around the nut. A
water flow passage can also be provided through the nut by one or more
apertures. This would eliminate the need for the ribs.
A pair of tool engaging cross slots 42 and 44 are formed in the upper end
of the retaining nut 32 (FIG. 2) for receiving a tool, such as a
screwdriver, for applying torque to the nut for rotating and driving it
inward or outward of the housing against the bias of spring 40. The slots
may accommodate a standard blade screwdriver or a Phillips screwdriver.
The nut is accessible exclusively and solely from or at the outlet of the
housing. Thus, the pressure of the valve may be adjusted by means of a
single tool (screwdriver) at the outlet while the valve is in place.
The housing is made up of two axially disposed, generally tubular pieces or
sections forming a generally tubular housing secured together by solvent
or sonic welding to form a unitary housing. The outlet section 46 of the
housing includes axially or forwardly extending rib members 48 extending
axially and inwardly for engaging an annular shoulder 50 on the retaining
nut for limiting the outward movement thereof. The ribs, together with
inwardly extending rib extensions 52 within the bore of 46, insure a flow
passage around the retaining nut, and the outer end of the retaining nut
is in its outward or retracted position.
The combination of the retaining nut and the valve stem 26 limit the inward
movement of the retaining nut toward the valve seat, and thus the maximum
pressure adjustment of the valve by action of the nut in relation to the
valve stem. As the nut moves inward, the valve stem projects into and
along the center of the nut and upward through the center of the bore into
the area of the tool slots 42 and 44, displacing a tool from the tool
slots. As the tool is displaced, it can no longer apply a torque to the
nut, and thus limits the inward movement of the nut. This limits the
compression of the coil spring 40.
The outward movement of the nu is limited by the engagement of annular
shoulder 50 thereon, with the shoulder formed by the forward or axial
extension of the rib members 48. Thus, the minimum and maximum pressure of
the valve may be limited in this manner by the range of movement of the
retaining nut.
In operation, the valve 10 may be assembled and preset to predetermined
pressures by adjustment of the nut inward and/or outward prior to its
installation. It may also be adjusted in the system to achieve a desired
pressure and/or flow. Referring to FIG. 3, an example of use of valves in
accordance with the invention is schematically illustrated in the form of
a sprinkler system having a main supply line 56, with a control or shut
off valve 58 supplying water to branch lines 60, 62 and 64, all of a
different level with a branch 60 being a lower level or elevation and 62
and 64 at yet higher elevations.
Check valves 72, 74 and 76 are placed at the juncture of each of the branch
lines, with the main supply line for each of the branch lines. With the
branch lines at different elevations, in order to achieve uniform
irrigation coverage by the sprinkler system, the check valves 72, 74 and
76 must be set different pressure settings. The valves must be set to at
the same time to permit the same flow rate to each the branch lines. The
valve 72 will be at higher pressure than valve 74, which will also be at a
higher pressure than valve 76. The pressure settings will be an amount to
compensate for the head due to the different elevations. Thus,
compensation can be made for different elevations within an irrigation
system, and enable one to achieve the same sprinkler overage at different
elevations within the same system.
While we have illustrated and described our invention by means of specific
embodiments, it should be understood that numerous changes and
modifications, may be made therein without departing from the spirit and
scope of the invention as defined in the appended claims. The further
assert and sincerely believe that the above specification contains a
written description of the invention and the manner and process of making
and using it, in such full, clear, concise, and exact terms as to enable
any person skilled in the art to which it pertains, or with which it is
most nearly concerned, to make and with which it further that it sets
forth the best mode contemplated by us for carrying out the invention.
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